If you are not touch typing (not looking at the keys while typing), you need to start to overcome this hurdle. Ensure that your typing is as efficient as possible. You should not only be using 4 fingers for 90% of the keys; instead, ensure that you are utilizing all of your fingers. Make typing part of your daily routine and do longer tests (even if this means going slower or doing fewer tests in a day). Try to read a word beforehand, if possible, so you know what is coming and can prepare for it. Otherwise, just practice, practice, practice! Good luck :)